Who built them and why? An amateur archaeologist tries to get to the bottom of some astonishing structures in Tibet and Sichuan Province, China

Martine "Frederique" Darragon set out from New York City for the hinterlands of western China and Tibet in 1998 to pursue an interest in the endangered snow leopard when she fell under the spell of another elusive phenomenon: old stone towers, some vaguely star-shaped and some more than 100 feet tall, scattered across the foothills of the Himalayas. Yet when she asked local residents about the towers—Who built them? When? Why?—nobody seemed to have a clue. What she had stumbled upon was rare indeed: a riddle in plain sight.

The structures became a near obsession for Darragon, 54, a self-described free spirit who is originally from Paris and boasts an eclectic résumé: an undergraduate degree in economics, founder of an organization that supports education in rural China, star polo player in Argentina, sailboat racer, artist. Over five years, she journeyed nine times to western China, where she saw nearly 200 of the towers in Sichuan Province and Tibet. She photographed and measured them, climbed into them when possible and carved off bits of wooden beams for analysis. She talked to local monks who said they'd found no mention of the structures in centuries-old monastery documents. Still, she did find a few references to the towers in some Chinese annals and, back in European libraries, in the diaries of 19th-century Western travelers to the region.

From 2000 to 2003, Darragon shipped pieces of wood from 32 towers to a laboratory in Miami for radiocarbon dating. The procedure yields an estimate of a material's age based on the level of the radioactive element carbon-14 in organic material. Most of the wood samples she had tested are several hundred years old; the towers from which they came are presumably about the same age. But one structure in Kongpo, Tibet, a day's drive from the capital, Lhasa, proved much older. It was likely built between 1,000 and 1,200 years ago, before Mongolian tribes invaded Tibet, around 1240. The dating method isn't definitive and it's possible that the wood used by some tower builders was already very old, in which case the structures may be younger. Still, scholars who've heard about Darragon's amateur archaeological sleuthing (the Discovery Channel aired a documentary about it last November) say it is valuable. "Her most important contribution is the attempt to date the towers," says Elliot Sperling, a Tibet scholar at Indiana University.

Local ignorance of the towers' original purpose may trace to the area's history and geography. A millennium ago, the place was dominated by mountain tribes that, over the centuries, have maintained their isolation; in some areas they can barely speak with one another. "People in one valley usually cannot understand what is said in the next valley," says Darragon, who speaks some Mandarin Chinese and some Tibetan. She wonders if knowledge of the towers that was once passed down orally may have been lost as dialects evolved or disappeared.

Darragon was especially intrigued by the more than 40 roughly star-shaped towers she encountered. Some have 8 points, others 12. In both configurations, star-shaped towers are rare, scholars say. At least two others can be found in Afghanistan, including the Minaret of Bahram Shah in Ghazni. Darragon speculates that the star shape makes the Chinese structures less susceptible to tremors. "All the people I asked in the villages said the towers resist earthquakes," Darragon says. And, in fact, she found that the only towers still standing in the Kongpo area of Tibet are star-shaped, though it's certainly conceivable that those structures have survived for reasons other than their supposed earthquake resistance.

The question remains: Why were they built? One idea is they served a religious function, perhaps representing the dmu cord that, according to Tibetan legend, is said to connect heaven and earth. "The towers might actually symbolize this cord," says Bianca Horlemann, an independent Tibet scholar in Bethesda, Maryland. Alternatively, some scholars suggest the structures were watchtowers or forts. "The towers were built for defense," says Marielle Prins, a linguist with the Southwest Institute for Nationalities in Chengdu, China. "Most of them are from the Jinchuan Wars [of the 18th century] in which the Chinese emperor spent large amounts of silver and human resources to pacify a small part of the Gyalrong area." Eric Mortensen, a Tibet scholar at National Taiwan University, who has traveled in the region, says the structures were "likely used as signal towers." He bases that conclusion on their locations, which generally provide a line of sight from one to another. Finally, the towers might have been status symbols erected by royalty—the Cadillacs of their day. "We can only speculate," says Sperling. "Our knowledge is extremely spotty."

Some scholars suggest that the towers are not so mysterious after all. "If there's any mystery surrounding them, it's no doubt partly a product of Western mythology around anything Tibetan and the fact that until recently the Chinese forbade access to the region," says Alex Gardner, a Buddhism specialist at the University of Michigan. "I don’t see how they could be called 'unknown' when they are visible for miles, and the region is crisscrossed with trading routes and now automobile roads."

Now that the region is being modernized, Darragon worries that turning the towers into tourist sites too quickly could do more harm than centuries of neglect have done. "Some are being restored in a disastrous way," she says, referring to a few whose crumbling upper reaches have been lopped off. Also, time continues to exact its toll; one of the oldest towers, Darragon says, collapsed last June. So she is trying to convince Chinese and Tibetan authorities, among others, to have UNESCO classify the towers as a World Heritage Site. The designation would likely help protect the towers and raise money to restore them. She is also trying to enlist Sichuan University's help in studying the structures. "Her work might lead to a further opening of the area to scholars," says Sperling. Meanwhile, the peripatetic Darragon is providing herself with an opportunity for more sleuthing by buying a house in a valley in the Kham area of China. The free spirit is settling down—next door to a tower.

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